Bioengineering can make a significant contribution to the Healthy People 2000 initiative by developing devices for disease prevention and control. This project is combining the efforts of two National Resources, the Wadsworth Center with expertise in imaging nervous system tissues and Cornell University's expertise in nanofabrication. Neural prostheses have tremendous potential to restore nervous system functions lost due to physical trauma or disease. Nanofabrication extends this approach to spinal cord and brain implants for stimulating and recording from single or small groups of neurons. The engineering of these devices is well developed; however, their tissue compatibility is a major limitation. In the brain, a "sheath" of cells surrounds the entire implant. Little is known about these cells and the characteristics of this sheath. We are characterizing the tissue reaction and determining which cell types contribute to the "sheath". The successful development of long-term implants requires biologically acceptable surfaces providing stable incorporation into brain tissue and low resistance connections with surrounding neurons. This project is studying the brain-neural prosthesis interface in order to improve the integration of neural prostheses into brain tissue. Test substrates were nanofabricated using semiconductor techniques. Continuous cell lines, primary cell cultures and automated analysis allowed the efficient testing of large numbers of surfaces, and analysis of cell attachment parameters, e.g. adhesion and strength of adhesion. It was found that cells from the continuous line attached in a single phase manner and that the primary astrocytes attached in a biphasic manner. Further, primary astrocytes from different brain regions attached with different kinetics indicating that the surfaces of the prostheses may have to be specifically designed for each brain region.